Abstract
A study was carried out to determine the influence of
the temperature and the reaction involved on the leaching of coppermatte.
Copper (Cu) bearing matte from Impala Refinery (Pty) Ltd
was used in the investigation. The experiments were conducted in a
leaching cell submerged in a water bath, with ammonia
concentrations (leaching solution) of 3.0M, temperature of 50°C,
60°C and 70°C, pH of 11 and for a time period of 130 minutes.
Leaching tests indicated that Cu recovery increased in the
temperature range 50°C - 60°C, however at a temperature of 70°C Cu
recovery decreases because of cementation process as nickel displace
copper. The shrinking core model was used to determine if the
leaching process was diffusion controlled, or chemical controlled, or
even mixed controlled. It was found that the leaching process could
not be determined using the shrinking core model due to the
cementation process of Cu. It was concluded that an increase in
temperature results in an increase in the Cu recovery however the
temperature should not be too high as cementation process increase
with increasing temperature.